1. Field of the Invention
This invention relates to anti-submarine weapons and, more particularly, to such weapons which may be directed over water to the vicinity of a submarine or similar target where the weapon, after entering the water, propels itself to home on the submarine.
2. Description of the Prior Art
The problems of anti-submarine warfare (ASW) have long been a serious concern of the United States and of many other nations. The capability of waging war effectively and of defending against attack by other nations depends in part upon protecting merchant shipping and naval vessels against attack by enemy submarines. Techniques for detecting enemy submarines have developed to a very sophisticated level. However, the ability to deliver a warhead to a point where destruction of the submarine is virtually assured has not kept pace.
Since World War II, the effective range of depth charges has been extended by the inclusion of rocket propulsion systems to direct the weapon farther out from the launching ship. While this extends the range and thus increases the safety of the launching ship, these weapons must still drop almost directly on the enemy submarine in order to be assured of a kill. More sophisticated ASW weapons have been developed in the form of anti-submarine torpedoes having the capability of detecting and homing on a submarine after the torpedo is in the water. The ASROC system has been developed to provide air launching and delivery of a torpedo to the vicinity of a submarine, where the torpedo enters the water and thereafter detects the submarine and homes on it for the kill. Such systems are incredibly complex and expensive, the cost of a single such weapon currently being on the order of $500,000 to $750,000. Moreover, such weapons are vulnerable to countermeasures generated by the submarine and furthermore are largely ineffective in shallow water (less than 100 fathoms) or against surfaced submarines. This means that enemy submarines can operate with considerable impunity on the surface or within very large areas along the continental shelves while preying upon coastal and intercontinental shipping within such regions. It is clearly extremely important to be able to provide an anti-submarine weapon which is more effective in operation, particularly with surfaced submarines and in shallow coastal waters, and is also more cost-effective in the sense of being simpler and less expensive to manufacture and operate.
Various examples of attempts to develop weapons for use in anti-submarine warfare are known in the prior art.
The Bartling et al U.S. Pat. No. 3,088,403 covers the currently operational ASROC weapon consisting of a MK 46 torpedo or depth charge, a rocket motor and a parachute pack. Upon entering the water, the torpedo separates from the other items to home on the submarine. However, detection of the submarine is limited to forward-looking detection systems which may not be able to detect a submarine laterally displaced from the water entry point unless the torpedo is initially directed in a hunt mode to circle and seek the submarine. The Bertheas U.S. Pat. No. 3,745,956 discloses a weapon which is rocket or gun launched to enter the water where it sinks to intercept the submarine. It has no underwater propulsion system but provides some control of sink direction in respone to acoustic detection of submarine noise. The Bradley U.S. Pat. No. 2,513,279 describes using reflected energy for homing or control in connection with all types of military systems, both over land or water, underwater, and between shore batteries and naval ships, to name a few. This patent appears to be a shotgun disclosure directed at every conceivable system using reflected energy for the purpose stated but fails to provide a truly operational disclosure of any system.
The Mueller U.S. Pat. No. 3,010,416, Sheffet U.S. Pat. No. 3,137,817 and Kalmus U.S. Pat. No. 3,121,228 relate to various types of radio frequency detecting and control systems.
The Gongwer U.S. Pat. Nos. 2,945,343 and 2,971,325, Torazzi U.S. Pat. No. 1,315,352, Zwicky U.S. Pat. No. 3,044,252, Chandler U.S. Pat. No. 3,087,451, and Hodgson U.S. Pat. No. 3,158,994 relate to various types of underwater vehicles and propulsion systems, some of which include warheads and control mechanisms to comprise homing torpedoes.
Despite the plethora of prior art attempts to solve the problems relative to anti-submarine warfare, specifically in underwater detection and propulsion, no solution such as is provided by the present invention has been heretofore developed.